From the past, a roll-to-roll vacuum vapor deposition apparatus that deposits, while paying out an insulation film such as a plastic film from a payout roller, a metal layer onto a surface of the film and taking up the film by a take-up roller thereafter is used in producing a film capacitor.
Incidentally, the film capacitor of this type includes a self-protection-function type in which a metal deposition layer formed on a surface of a film is fragmented into a plurality of capacitor pieces, and the adjacent capacitor pieces are mutually connected at a junction portion that is formed of the same deposition layer and has a narrow width. In the film capacitor of this type, the junction portion is fused when an insulation breakdown occurs in a part of the film capacitor (fuse function) so that an insulation breakdown area of the capacitor is suppressed at minimum on an individual piece basis.
When producing such a self-protection-type film capacitor by the roll-to-roll vacuum vapor deposition apparatus described above, a mask forming means for forming a mask pattern that defines a deposition area of the metal layer with respect to a deposition surface of the film is interposed between the payout roller and an evaporation source (see, for example, Patent Document 1 below).
As the mask forming means, while nipping the film between a printing roller (plate cylinder) and a backup roller (impression cylinder) and conveying it, an oil for forming a mask pattern that has been transferred onto the printing roller from an oil supply source via a transfer roller is successively transferred onto the deposition surface of the film from the printing roller. Accordingly, self-protection-function-type film capacitors each having a capacitor piece in an arbitrary shape are produced successively.
Meanwhile, in a roll-to-roll vacuum vapor deposition apparatus of the related art, the printing roller and the transfer roller have been provided to a member fixed in the vacuum chamber. Further, such a roller group has been adjusted in the atmosphere, and the vacuum chamber has been exhausted thereafter.
However, the vacuum chamber is deformed to some extent when a pressure inside is reduced. In particular, recent vacuum chambers are increased in size, with a tendency that a deformation amount of the vacuum chamber at a time of exhaustion increases. A positional accuracy of a mask forming unit is required to be 1/100 mm or less, but a deformation of the vacuum chamber may be caused in an order of about 1 mm. Therefore, even when the roller group of the mask forming unit is adjusted in the atmosphere, the influence of the deformation may affect pattern formation. Thus, it has been necessary to adjust the roller group in consideration of the deformation amount and repeatedly perform the adjustment in the atmosphere and a post-exhaustion check, thus resulting in an increase in the number of processes.
Patent Document 1: Japanese Patent Application Laid-open No. Hei 10-81958